The present invention relates to patch bags, particularly patch bags used in the packaging of bone-in meat products. Such patch bags have a protective patch adhered directly thereto, the protective patch preventing bone puncture, or reducing the likelihood of bone puncture.
Bags having patches adhered thereto have for some time been used in the packaging of various bone-in meat products. The patches provide additional resistance to puncture of the bag by the bone in the meat product. In this manner, fewer xe2x80x9cleakersxe2x80x9d result, and the possibility of contamination is also reduced. A variety of patch bags have been used for the packaging of a variety of meat products. Most of the patch bags have been end-seal patch bags having one or two patches adhered to the outside surface of the bag.
One of the patch bags which has been commercialized for several years is a patch which covers a portion of one of the side edges of the bag. However, the patch extends over less than 50 percent of the distance around the bag because the entirety of the patch is applied to a single lay-flat side of a film tubing which is thereafter converted into a bag via sealing and cutting. However, some bone-in meat cuts present bones which impact the bag at a variety of points which, taken together, require the presence of more than one patch. The presence of a second patch presents an efficiency challenge in that it is difficult to adhere patches to opposite sides of the tubing in a single pass, thereby necessitating a less-efficient process which utilizes multiple passes. Moreover, the presence of the second patch presents a technical challenge in that the second patch must not only be registered and aligned with respect to the bag tubing film, the second patch must also be registered with respect to the first patch which is on the other side of the bag.
Another patch bag which has also been commercialized for several years is an end-seal patch bag having one patch adhered to each lay-flat side of the bag, with the patches covering across the entire width of the bag, each of the patches overhanging each of the bag side edges. Those patch portions which overhang the side edges are adhered to one another. Thus, the combination of the two patches provides effective patch coverage around the entire bag. However, producing this bag presents even greater the technical registration and alignment challenges than for the two-patch bag described above, because of exposed adhesive if the two patches are less than perfectly aligned with one another. Moreover, additional technical challenges are present due to the presence of exposed adhesive on the extending portions of the first patch applied, i.e., before the second patch is applied, as well as from excess adhesive which exudes from between the extended portions of the patches.
It would be desirable to avoid the technical and efficiency challenges described above, while providing ample patch coverage for bone-in meat cuts which impact the bag in areas which require a patch which covers more than 50 percent of the distance around the bag. Applicants have invented a patch bag having a patch which provides patch coverage more than 50 percent of the distance around the bag. Applicants have also invented a process for making a patch bag which, through the use of a patch which covers more than 50 percent of the distance around the bag, avoids the efficiency challenges and technical challenges in the making of the patch bags described above.
As a first aspect, the present invention pertains to an end-seal patch bag comprising a seamless, tubular bag having an open top, a first side edge, a second side edge, a bottom edge, an end seal, and a patch adhered to the bag, wherein the patch extends across more than 50 percent of a total transverse cross-sectional surface of the bag. Preferably, the patch extends across at least 50 percent of a first lay-flat side of the bag. Preferably, the patch also extends across at least 10 percent of a second lay-flat side of the bag; more preferably, at least 15 percent of the second lay-flat side of the bag; still more preferably, at least 20 percent of the second lay-flat side of the bag, yet still more preferably, at least 25 percent of the second lay-flat side of the bag; even yet still more preferably, at least 30 percent of the second lay-flat side of the bag; even more preferably, at least 35 percent of the second lay-flat side of the bag.
Preferably, the bag comprises a first heat-shrinkable film and the patch comprises a second heat-shrinkable film. Preferably, the first heat-shrinkable film is a multilayer film and the second heat-shrinkable film is a multilayer film. Preferably, the first heat-shrinkable film comprises: (A) an outside abuse layer comprising at least one member selected from the group consisting of ethylene/alpha-olefin copolymer having a density of from about 0.85 to 0.95, propylene/ethylene copolymer, polyamide, ethylene/vinyl acetate copolymer, ethylene/methyl acrylate copolymer, and ethylene/butyl acrylate copolymer; (B) an inner 02-barrier layer comprising at least one member selected from the group consisting of ethylene/vinyl alcohol copolymer, polyvinylidene chloride, polyamide, polyester, polyacrylonitrile; and, (C) an inside sealant layer comprising at least one member selected from the group consisting of thermoplastic polyolefin, thermoplastic polyamide, thermoplastic polyester, and thermoplastic polyvinyl chloride.
Preferably, the second biaxially-oriented, heat-shrinkable film comprises at least one member selected from the group consisting of ethylene/alpha-olefin copolymer having a density of from about 0.85 to 0.95, propylene/ethylene copolymer, polyamide, ethylene/vinyl acetate copolymer, ethylene/methyl acrylate copolymer, and ethylene/butyl acrylate copolymer. More preferably, the second biaxially-oriented, heat-shrinkable film comprises at least one member selected from the group consisting of linear low density polyethylene, homogeneous ethylene/alpha-olefin copolymer, and ethylene/vinyl acetate copolymer.
Preferably, the patch is adhered to the bag with an adhesive. Although the patch can be adhered to an inside surface of the bag or an outside surface of the bag, preferably the patch is adhered to the outside surface of the bag, so that the product placed in the bag is not exposed to the adhesive used to adhere the patch to the bag.
Although more than one patch can be adhered to the end-seal bag, preferably only one patch is adhered to the bag. Although a single patch extends more than half way around the end-seal bag, the patch can extend across part or all of a first lay-flat side of the end-seal bag. Preferably, the patch extends across the entirety of the first lay-flat side of the end-seal bag, as well as covers a portion of the length of both side edges of the end-seal bag, as well as covers two discrete regions of the second lay-flat side of the end-seal bag.
The bag film and/or the patch film can comprise a crosslinked polymer network. Preferably, both the bag film and the patch film comprise a crosslinked polymer network.
While the patch can have a length less than, equal to, or even greater than the length of the bag, preferably the patch has length which is less than the length of the bag. Although the patch can extend to the top edge of the bag and/or to the bottom edge of the bag, preferably the patch does not extend to either the top edge of the bag or the bottom edge of the bag, so that an end-seal can be made (without having to seal through the patch film) across the bag in an uncovered region near the bottom edge of the bag, and so that a top seal can be made (again, without having to seal through the patch film) across the bag in an uncovered region near the top edge of the bag.
Although the patch extends more than half way around the bag, the patch can extend less than all the way around the bag, or even all the way around the bag. If the patch extends around the entirety of the bag, the patch can have a width in excess of the circumference of the bag, with the excess patch width being taken up in the patch being adhered to itself If this excess patch is adhered to itself, it can be adhered in a lap configuration or in a fin configuration, i.e., one side of the patch film is adhered to the other side of the patch film (a lap configuration), or the adherence can be of the same side of the patch film to itself (a fin configuration).
As a second aspect, the invention pertains to a side-seal patch bag comprising a tubular bag having an open top, a seamless bottom edge, a first side seal, and a second side seal, the tubular bag having a patch adhered thereto, the patch coveting at least a portion of the bottom edge of the bag, the patch extending across more than 50 percent of a total longitudinal cross-sectional surface of the bag. Preferred side-seal bags in accordance with the present invention are analogous to preferred end-seal bags in accordance with the present invention.
As a third aspect, the present invention is directed to a process for making a patch bag, comprising: (A) adhering a first portion of a patch film across a first lay-flat side of a seamless, tubular, lay-flat bag film, the patch film being adhered to the first lay-flat side so that only a first portion of the patch film is adhering thereto, with a second portion of the patch film extending outwardly from the first side edge of the tubular, lay-flat bag film; (B) wrapping the second portion of the patch film around the first side edge of the tubular bag film, so that the second portion of the patch film is adhered to a first region of a second lay-flat side of the tubular bag film; and (C) sealing the tubular bag film to itself so that a patch bag is formed.
Preferably, the wrapping of the second portion of the patch film around the first side edge of the tubular bag film is carried out by inflating the tubular bag film and passing the inflated tubular bag film against a contact roll which presses the second portion of the patch against the tubular bag film. The contact rolls can be smooth rolls (e.g., made of polished metal), brush rolls, or even blowers. Alternatively, nip rolls having a length less than lay-flat width of the inflated tubular bag film could be used, so that the inflated bubble would be contiguous.
Although the tubular bag film could be continuously or intermittently forwarded to the contact roll, preferably the tubular bag film is continuously forwarded to the contact roll. Preferably, the inflated tubular bag film is maintained in a vertical orientation. Alternatively, the inflated tubular bag film could be maintained in a horizontal orientation during the wrapping of the second portion of the patch against the inflated tubular bag film.
Although one or more contact rolls can be used to wrap the second portion of the patch film around the first side edge of the tubular bag film while the bag film is inflated, preferably a plurality of contact rolls are used to sequentially wrap the patch film around the side edge of the bag film. The contact rolls can be driven or freewheeling. For reasons of simplicity and economy, preferably, the contact rolls are freewheeling. If the contact rolls are driven, preferably they are driven so as to urge film further in the direction of its movement, so as to achieve a smooth wrapping of the patch film to the bag film.
If a first portion of the patch film extends across an entirety of the first lay-flat side edge of the tubular bag film, and a second portion of the patch film extends outwardly from the first lay-flat side edge of the tubular bag film, and a third portion of the patch film extends outwardly from the second lay-flat side edge of the tubular bag film, the process can utilize two separate sets of contact rolls to wrap each of (a) the second portion of the patch film across the first bag side edge and onto the first region of the second lay-flat side of the bag tubing, and (b) the third portion of the patch film across the second side edge and onto the second region of the second lay-flat side of the bag tubing, respectively.
The adhesion of the patch to the bag film can be accomplished and/or enhanced by subjecting the patch film to at least one member selected from the group consisting of corona treatment, primer application, and flame treatment. Alternatively or additionally, a surface of the tubular bag film can be subjected to at least one member selected from the group consisting of corona treatment, primer application, and flame treatment. Of course, preferably the surface subjected to such treatment is the surface to which the patch is to be adhered.
The adhesive can be continuously applied to a continuous patch film which is thereafter cut into discrete pieces which are adhered onto separate locations on a continuous bag film tubing, with the resulting laminate thereafter being sealed and cut to form patch bags.
The sealing and cutting can be carried out so that an end-seal patch bag is produced, and/or so that a side-seal patch bag is produced.
The process can be carried out so that the patch has a total width of from about 105 to 250 percent of the width of the lay-flat bag film; more preferably, from about 105 to 210 percent of the width of the lay-flat bag film, still more preferably, from about 105 to 180 percent of the width of the lay-flat film.
As a fourth aspect, the present invention pertains to a packaged product, comprising: (A) a package comprising an end-seal patch bag comprising a seamless tubular bag having a first side edge, a second side edge, a bottom edge, a bottom end seal, and a top end seal, and a patch adhered to the bag, wherein the patch extends across more than 50 percent of a total transverse cross-sectional surface of the bag; and, (B) a meat product in said package, the meat product comprising bone. Preferably, the meat product comprises at least one member selected from the group consisting of poultry, pork, beef (including veal), lamb, goat, horse, and fish; more specifically, ham, sparerib, picnic, back rib, short loin, short rib, whole turkey, pork loin.
As a fifth aspect, the present invention pertains to a packaged product comprising: (A) a package comprising an side-seal patch bag comprising a tubular bag having a seamless bottom edge, a first side seal, a second side seal, and a top seal, the tubular bag having a patch adhered thereto, the patch covering at least a portion of the bottom edge of the bag, the patch extending across more than 50 percent of a total longitudinal cross-sectional surface of the bag; and (B) a meat product in said package, the meat product comprising bone. Preferably, the meat product is as described for the fourth aspect of the present invention.